In Republican Rome, as in modern democracies, effective communication was vital for winning elections, and Cicero was the most accomplished public speaker in Roman history.

What made Cicero an unsurpassed orator? Besides his brilliance and relentless drive to excel, Cicero mastered rhetorical theory from classic handbooks like Aristotle’s Rhetoric. He even contributed to the genre himself. A number of devices and principles from these ancient handbooks have withstood the test of time. Here are just a few that we have seen, two millennia later, in the current presidential campaign:

Enthymeme.

In a 140-character world, brevity is digital wit. Hence the attractiveness of the enthymeme, a type of syllogism in which the speaker intentionally withholds the premises or conclusion of an argument. The enthymeme works because of succinctness, simplicity, and the active participation of the audience, who has to supply the missing information. Aristotle noted its powerful popular appeal in democratic Athens.

Among contemporary politicians, Donald Trump stands out for arguing in enthymematic form in debates, in media interviews, and especially on Twitter.